Should we write pre-trial or pretrial? Non-statutory or nonstatutory? Co-sponsor or cosponsor?
As legal writers, we often have to decide whether to use a hyphen for a prefix. By the way, no hyphen in prefix, despite the hyphen in the title; I was just being clever. In this post I’ll discuss the default rule for hyphenating prefixes as well as the exceptions. (FYI: This blog breaks words at the right margin and inserts hyphens I can’t control. Sorry.)
The default rule is to omit most hyphens: pretrial, nonstatutory, cosponsor. According to Joan Magat in The Lawyer’s Editing Manual, the same rule applies to multiracial, nongovernmental, semiliterate, and underutilize. Even when the result is a doubled letter, omitting the hyphen is generally correct, according to Bryan Garner’s Redbook. So interrelate, misspell, overrate, posttrial, preempt, and reelect. Omitting the hyphen can produce words your spell-checker doesn’t recognize, but “they are nonetheless correct,” according to June Casagrande in The Best Punctuation Book, Period.
Now the exceptions.
Certain prefixes always take a hyphen, and Magat and Garner agree on four that require a hyphen in legal writing: all-, ex-, quasi-, and self-. So all-encompassing, all-knowing, ex-convict, ex-president, quasi-contract, quasi-public, self-assessment, and self-serving.
When the prefix precedes a capital letter or a numeral, use a hyphen. Casagrande, Garner, and Magat agree on this: non-American, anti-Semitic, post-1986, and pre-9/11.
Bring in a hyphen when omitting it could create a miscue, an ambiguity, or confusion—because the unhyphenated word looks like another word:
- Judge Kean spent most of her pre-judicial career at Lowery & Townes.
- Forbes rejected the Petitioner’s request to re-sign the contract.
- The incident resulted from an unexpected re-formation of river ice.
- Andrick’s video was meant to re-create the events at issue.
The experts also recommend a hyphen when omitting it could create an awkward or hard-to-pronounce compound. Here you must exercise editorial judgment; as you’ll see, the experts’ examples aren’t always consistent with other guidance. Here are the examples the experts say should be hyphenated:
- Casagrande: anti-inclusive, intra-arterial, ultra-apathetic
- Garner: anti-intellectual, post-sentencing, pro-abstinence
- Magat: co-opt, co-worker, non-odious
Thus, we’ve arrived at our guidelines for hyphenating prefixes.
A no-hyphen approach is preferred, with three exceptions: (1) with all-, ex-, quasi-, and self; (2) before numerals and capital letters; and (3) to avoid awkwardness—exercising your best editorial judgment.
For detailed guidance, see The Chicago Manual of Style § 7.79, which is followed in § 7.85 by a 9-page table table with rules for hyphenating specific prefixes and words. Magat’s book, The Lawyer’s Editing Manual, also contains a list of prefixes that are generally unhyphenated, with exceptions.